    true
    (catch java.sql.SQLException ex
      ;; did not get the lock
-     false))
-  )
+     false)))
 
 (defn group-row-updates [recs]
   (reduce (fn [acc r]

(defn clear-registry []
  (reset! registry         {})
  (reset! indexed-registry {}))

;; (clear-registry)

(defn register-listener [listener-name dbname schema-name table-name f]
  (swap! registry assoc listener-name {:dbname dbname

(defn process-row-changes [conf conn]
  ;; obtain mutex, nowait
  ;; TODO: handle failure to get lock (probably an exception)
  (let [dbname        (-> conf :conf :subname)]
    (jdbc/transaction
     (if (obtain-mutex conf conn)
       (do
